Lock nut making machine



Oct. 1, 1946, c. D. TRIPP LOCK NUT MAKING MACHINE Filed Jan. 7, i944 7 Sheets-Sheefi 1 C. D. TRIPP LOCK NUT MAKING MACHINE.

Filed Jan. 7, 1944 Oct. 1, 1946. 2,408,457

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LOCK NUT MAKING MACHINE Filed Jan. 7, 1944 I 7 Sheefs-Sheet 3 'r I a Oct. 1, v c D .TR |PP I LOCK NUT MAKING MACHINE Filed Jan. '7, 1944 7 Sheets-Shegt 4 c 1946- c. D. TRlPP Lock NUT MAKING MACHINE Filed Jan. 7. 1944 7 Sheets-Sheet 5' u rlllfvg m ,IIIII EEIEEEISE Oct. 1, 1946.

c. TRIPP 2,408,457

LOCK NU'I MAKING MACHINE Filed Jan. '7, 1944 "r Sheets-Sheet 6 E151 #7? K .1 I

Oct. 1, 1946. c. D. TRIPP 2,408,457

LOCK NUT MAKING MACHINE Filed Jan. 7, 1944 7 Sheets-Sheet 7 Tam i 75 (Zesiri Patented Oct. 1, 1946 Chester D. Tripp, Chicago, 111.

Application January 7, 1944, Serial No. 517,409

The present invention relates to an improved machine for making lock nuts and more particularly to a machine for converting standard quantity production nuts into lock nuts having a predetermined locking'or gripping force.

The need for lock nuts having definitely predetermined looking or gripping forces within close tolerances has been recognized for many years. While satisfactory nuts of special construction have been produced, they are relatively expensive and their use has not been practical except where expense can be disregarded. In spite of, repeated attempts, no wholly satisfactory machine for converting standard quantity production nuts into lock nuts having closely 24 Claims. (01. -72) surface area to modify the helix angle of a porcontrollable predetermined locking or gripping forces was developed until that shown in the present application was devised.

Some of the prior efforts to produce methods and machines for making lock nuts havingclosely controlled gripping forces from standard quantity production nuts are shown in the patentsto Roof 1,209,501; Chadwick1,391,170; Endsley et a1. 1,753,238; Sharp et al. 1,753,250; Sharp 1,795,-

517; Sharp 1,795,518; and Sharp 2,007,310 and Wilson 2,000,056. While these machines and methods produce grip nuts, variations of 20% or more in uniformity of the gripping force, even when the machines are properly maintained, were customary in a run of standard nuts.

by applicants company, the Grip Nut Company, to imp'rove such machines, they were un'ableto more closely control the gripping forces because In spite of the expenditure of large sums of money of machine weaknesses and the variations in d Patent No. 2,000,056, in which a fluid or spring 1? pressure or impact actuated member carries the indenting tool, but it is open to the objection that it is subject to severe wear, it is difficult to feed the nuts through the machine, and the tool is ing predetermined locking force. To applicants knowledge the apparatus of the Wilson patent has not gone into commercial use.

In my co-pending application Serial No. 477,-

not shaped to produce a successful lock nut hav- T 600, filed March 1, 1943, for Lock nut and meth- 0d of making same, I have disclosed, a method of converting standard nuts into novel effective lock nuts by indenting a face of the nut by means of shallow indentations of rapidly increasing tion of the threads of the nut adjacent the indentation-sin proportion to the depth and area of theindentation, and which overcomes all of the disadvantages of the foregoing prior art 3 methods heretofore proposed.

It is themajor object of this invention to providea novel apparatus for carrying out the method of the foregoing co-pending application and to provide otherimprovements and refinements in lock nut production methods and apparatus, as will hereinafter appear.

Another important object isjto provide a machine for making lock nuts embodying means for subjecting the nut to a predetermined indenting pressure which bears a definite relation to the area of the indenting tool,thereby eliminating machine weaknesses and making possible the production of effective lock nuts having substantially more uniform locking characteristics from standard commercial nuts, irrespective of the thicknessand density of the'n'uts.

' Another important object is to provide a novel machine for making inexpensive lock nuts having definitely predetermined locking or gripping forces.

A further object resides in the provision of a' machine embodying novel means for compensating for the variations in height and density of standard quantity production nuts, so as to assure the production of lock nuts having substantially identical locking or gripping forces. I More specifically, the novel apparatus comprises a die and a die actuating nut backing assembly operable to indent a face of a standard quantity production nut over a rapidly increasing surface area, the die and nut being urged together by a predetermined resilient pressure whereby the uniform resistance of the metal of the nut to displacement of the metallaterally of the applied force balances the resilient pressure and predetermines the depth of indentation, irrespective of nut thickness.

Another object of the present invention resides in, the provision of a nut indenting machine designed toindenta face of a standard quantity production unt in such a. manner that only the helix angleof the thread is altered to secure the locking ef e A. still further object of the present invention is'to provide s, machine for pressinga'standard quantity production nut between a pair of rela-' tively movable members, one of which is backed by a, predetermined resilient force, and designing one ofsaid members to indent a, face of the nut axially adjacent the root of the thread and laterally outwardly over a rapidly increasing surface area until the resistance of the metal of the nut to lateral deflection balances the resilient force.

A further object is to provide a die of novel form for indenting the face of a nut adjacent the root of the thread in such manner that only the helix angle of the thread is altered and yet a superior locking action is secured.

Another object is to provide a machine for making lock nuts embodying novel means for feeding the nuts to the die and for removing them from the machine upon conclusion of the die pressing operation.

The invention also aims to provide novel hydraulic and pneumatic controlling mechanisms for insuring proper operation of the machine of the invention, including novel means for establishing and controlling the fluid back up pressure; for making up losses of fluid from the system; and for scavenging fluid leaking past the pistons.

Another object is to provide a novel lock nut machine embodying a vertically rec-iprocable table on which the nuts are supported and fed toward the die; a novel yielding mechanism for backing up the die and predeterrnining the ultimate pressure developed between the nut and die, irrespective of the nut thickness; and a novel assembly for feeding nuts into operative position on the table which is synchronized with reciprocations of the table to automatically remove a finished nut and feed a fresh nut into position for every cycle of operation.

A further object is to provide a novel method of and apparatus for removing a nut from the sphere of action of a die pressing or other machine for producing an operation upon the nut.

The apparatus of the present invention contemplates a nut supporting member and an aligned indenting member or die disposed in predetermined spaced relation. One of said members, the pressing member, is designed to have a predetermined constant length of movement toward the other to press a nut therebetween. The die, which may be on either member, is formed with shallow indenting means, the surface area of which increases in a predetermined rapidly increasing ratio to the length, designed to simultaneously deflect the metal surrounding the bolt opening axially and laterally with respect to the direction of movement in all directions away from the opening over a rapidly increasing area. The relative movement of the members is automatically limited by a suitable yielding pres-' sure of predetermined force. Since the length of movement of the pressing member is constant and the resistance of metal having substantially the same physical characteristics to lateral deflection is reasonably uniform, irrespective of the height of the nut, it will be appreciated that the predetermined yielding pressure will be overcome at the instant the opposing pressure, determined by the area of the indenting means multiplied by the pressing force, overcomes the yielding pressure and that further movement of the pressing member causes unitary movement of the pressing member and die. It follows, therefore, that the depth and area of indentation is directly proportional to the yielding force and that substantially identical indentations may be made in successive nuts made up from metals having substantially the same physical characteristics irrespective of the height and minor variations in the density of the nuts.

The apparatus of the present invention contemplates applying the indenting means to a face of the nuts surrounding the threaded opening at spaced points 9 with their points of maximum indentation at a predetermined distance outwardly from the root of the nut thread. While any suitable distance may be used, the present preferred distance is 3% of an inch beyond the root diameter in /2 inch nuts and a similar proportional relationship on nuts of differing sizes. Such application of the indenting means results in' an axial distortion only of the helix of the nut thread over a rapidly increasing length of the helix. This forms knobs ID on the flanks of about two threads of nut II as shown in Figure 11 of the drawings. These knobs bind on the flanks of the bolt thread in varying degrees, depending upon the area and height of the knobs, and the size of these knobs is proportional to the area and depth of the indentations. Sincethe locking effect obtainable results from the degree of binding, it will be clear that the locking force is controllable by varying the yielding backing force and that the yielding force required to obtain a desired locking force on nuts of a particular size can be readily determined by trial and thereafter assured by maintaining the desired yielding force. Furthermore, the knobs or gripping areas of the nut thread may be varied to increase or decrease the frictional resistance between the nut and bolt threads by varying the yielding force or the ratio of the area and height of the indenting means. By employing this novel apparatus, uniformity of the locking force to a variable of less than 15% may be readily obtained in standard production nuts of a given size and material, irrespective of the variations in the height and minor variations in the density of the nuts.

Referring to the drawings:

Figure 1 is a front elevational view of a machine made in accordance with the present in- 45 vention.

Figure 2 is a side elevational view of Figure 1 viewed from the left hand side thereof.

Figure i3 is a vertical sectional view taken on line 3-3 of Figure l and looking in the direction 50 of the arrows.

Figure 4 is an enlarged sectional view illustrating the platen reciprocating mechanism and air valve operating means employed in the machine of Figures 1 to 3.

Figure 5 is a detailed sectional view taken on line 5-5 of Figure 4 looking in the direction of the arrows.

Figure 6 is a detailed sectional view of one of the liquid backed pistons for yieldingly resisting 6o upward movement of the indenting dies used in the machine of Figures 1 to 3.

Figure '7 is a detailed sectional view of the fluid pump used in the machine of Figures 1 to 3 to maintain suflicient liquid in the tank supplying 65 the piston of Figure 6.

Figure 8 is a side elevational view of an indenting die made in accordance with the present invention.

Figure 9 is a bottom plan view of the die of 7 Figure 8.

Figure 10 is a top plan view of a nut after it has been indented by the machine of Figures 1 Figure 11 is a sectional view of the nut of Fig- 75 ure l0 taken substantially on the line H--ll of Figure looking in the direction of the-arrows. Figure 12 is a fragmental'perspective view of the platen, dies, nut retaining structureand nut feeding mechanism of the machine of Figures substantially on the line l3-l3 of Figure. 1 looking' in the direction of the arrows.

Figure 14 is a detailed sectional view taken substantially on the line l4l4 of Figure 13 looking in the direction of the arrows.

Figure 15 is a detailed sectional view of a telescopic connecting rod employed for operating the nut feeding mechanism of Figures 12-14.

Figure 16 is a detailedsectional view taken substantially on the line l6-l 6 of Figure 14, looking in the direction of th arrows, and

Figure 17 is a detailed sectional view taken substantially on the line I'l-l'! of Figure 13 looking in the direction of the arrows.

With continued reference to the drawings, wherein like reference characters are employed throughout to designate the same parts, the nut indenting machine of the present invention is made up of a base B; a supporting super-structure C mounted on base B; a fluid reservoir R mounted on base B; a pressure tank 'I mounted on super-structure C; a movable platen H; a nut feeding mechanism F; a driving mechanism D and an electric motor M for driving platen H and feeding mechanism F; an anvil or die A operatively associated with movable platen H'so as to press a nut between the die and the platen; a piston P, the upper surface of which is subjected to the pressure in tank T through. a column of liquid; a liquid pump Q carried by superstructure C and connected to reservoir'R and tank T to supply liquid to tank T when desired; a pressure gauge G designed to indicate the pressure in tank T; an air system S leading to tank 'I. and'to a valve V and arranged to supply air to a nut discharge .mechanism E for ldischarging indented nuts from platenH. Y 1 a .It will be appreciated, however, that platen H may be replaced by a fixed platen and the pistons P and associated dies A mounted for movement toward the platen,-or the dies A alone may be made movable and'the fluid backing means applied to the fixed platen without departing from the spirit of the present invention. s Referring to Figures 1, 2'and 3, base 513 comprises a pair of spaced supportinglegs i5-adapted to rest on the floor and having tracks I6. ,Each leg 15 is provided with an upwardly extending portion I! at one end and a second upwardly extending portion [8 at the other-end. Each of these portions is respectively provided with'slots l3 and (Figures 2 and 3). Disposed in track l6 are spaced rocker members 2| secured to plate 22 by means of bolts 23 (Figure 1), Rocker mem bers 2| also are provided with bolts 24 extendingthrough slots l9 and and receiving nuts 25 to lock the rockers in any desired adjusted position along track 16. It will thus be appreci ated that base B provides a structure which may be readily adjusted to level base plate 22, irrespective of the unevenness of the floor. upon which the machine is mounted.

superstructure C comprises end walls 26 integrally formed on plate 22 and interconnected at the top by a bridge member 21. End walls 26 adjacent the front of the machine and plate 22 are recessed as shown at 28 (Figure 2) to'receive journal brackets 29 bolted to plate 22 by meansof cap screws 3|. Journal brackets 29 receive sleeve bearings 32' and are provided withoil cups 33 for lubricating bearings 32 in well known manner. Rotatably mounted in bearings 32 is a main drive shaft 34 having a large pulley wheel 35 secured to one end and a sprocket wheel 36 secured to the other end.

Shaft 34 between journal" brackets 29 is provided with spaced cams 31 for a purpose to be hereinafter pointed out. Motor-shaft 38 of motor M is provided with a pulley wheel 39 adapted to drive pulley wheel 35 by means of a belt in well known manner.

Plates 42 bolted to plate 22 along the front and rear edges are provided with upstanding columns 43 having vertically extending passages 44 (Figures 3 and 4) adapted to be aligned with similar passages 45 formed in base plate 22, Passages 44 and 45 are adapted to receivepins 46.- At their lower ends, pins 46 are threaded to receive a pair of lock nuts 41 (Figure 3) retaining buffer springs 48 between the bottom of base plate 22 and the lock nuts. While any suitable connection between pins 46 and platen H may be employed, it is preferable to form pins '46 with an integral collar or flange 58 having its upper surface:59 accurately machined to receive the under surface of platen H. The upper ends 6| of pins 45 are threaded to receive the spanner nuts 62 which are screwed down to clamp platen H between nuts 62 and flanges 58. Such a structure will eliminate any tendency of platen H'to cock with respect to pins 46.

Platen H on its lower face and along the transverse center line is provided with journal brackets 49 secured thereto by cap screws 5| (Figures 4 and 5). Journal brackets 49 receive a transversely extending shaft 52 having cam engaging rollers 53 rotatably mounted thereon. Suitable spacing sleeves 54 are disposed between rollers 53 and journal brackets 49 to maintain the rollers in proper axial alignment with respect to cams 31. Platen H is suitably recessed at 55 to clear rollers 53 and has V-guide members 56 bolted to its upper surface (Figures 5, 12 and1'3) and sliding in V-ways 51 in'walls 26 to guide platen H in its reciprocating movement and prevent cooking of platen H in operation.

From the foregoing description, it will be clear that motor M through pulley 39, belt 4|, pulley wheel 35, shaft 34, and cams 31 will impart a smooth vertical reciprocatory movement of constant length to platen H and members 56 and ways 51 will guide the platen in its reciprocating movement. Furthermore, it will be clear that buffer springs 48 will maintain rollers 53 in engagement with cams 3! during all phases of operation of the machine and yieldingly resist up- V ward movement of the platen and dampenany shocks resulting from the cam drive. As a consequence, platen H will be reciprocated in such a manner that undesired shocks will not be transmitted to the superstructure and thebase.

On its upper face platen H is provided with two pairs of spaced guide rails 63 secured to platen 'H by bolt and washer assemblies 64 (Figures 12 69 to connect feed bars 6'1 to a suitable nut feeddriving mechanism to be hereinafter described. 6 Secured; tothe upper face of platen. I-Lin axial alignment with spaces II provided between guide rails 63 are nut positioning members 12 having longitudinally extending bolt receiving slots I3 for longitudinally adjustably mounting members 12 on platen H. Members I2 at their ends adjacent rails 63 are provided with V-shaped notches or pockets 75 for receiving a nut. By reason of the provision of slots I3 members I2 may be adjusted individually longitudinally along the surface of platen H to align each nut receiving pocket 15 with its associated die mechanism A. It will thus be seen that means is provided for adjusting the machine to accommodate various sizes of nuts merely by loosening screws 14, adjusting the position of pockets I5, and utilizing a die mechanism A of appropriate size.

The nut feed driving mechanism of the present invention includes a lever '56 pivoted at E7 on a bracket I8 bolted to front plate 42 by bolts I9 and provided at its upper ends with spaced legs 8| having slots 82 therein (Figures 1, 3, 12 and 14). The slotted portions of legs 8! are disposed within the bifurcated ends 69 of feed bars 6'! and maintained in assembled relation by means of threaded pins 93 passing through suitable openings in bifurcated end 69 of feed bar 6! and retained in place by means of nuts 84. The lower end of lever I6 is pivotally connected at 85 to the free end of member 86 of a telescoping conneoting rod 81. The free end of the other member 88 of connecting rod 8! is pivotally connected to a crank disk 89 carried at one end of a crank shaft 9| and positioned with respect to axis of shaft 9| and cam 31 so nut II will be gripped at the instant die mechanism A contacts the nut. This connection comprises a pivot screw 92 (Figures 1, 3 and 15). Member 88, as clearly seen in Figure 15, is hollow and receives a coil spring 93. One end of spring 93 abuts against an inner end wall (not shown) of member 83 and the other end abuts an enlarged head 94 formed on the telescoping end of member 86. Member 68 at its telescoping end is provided with a threaded cap 95 which is centrally apertured to receive the intermediate portion of member 86. In order to assemble cap 95 and member 86, head 94 is preferably removably associated with member 86 as by screw threads indicated at 96. Crank shaft 9| is journalled in brackets 98 and 99 (Figures 1 to 3) bolted respectively to plate 22 and a member 2| of the supporting base. At its outer end crank-shaft 9I is provided with a sprocket wheel II]! of identical size to the previously described sprocket wheel 36 which is driven from sprocket wheel 36 by means of a sprocket chain I62. Sprocket chain I62 is tensioned by an idler wheel I03 journalled in a bracket I04 pivoted on side wall 26 and adapted to be bolted in predetermined adjusted relation by means of a cap screw I05 threaded into side wall 26. It will thus be seen that shafts 34 and 9I rotate at the same speed.

Lever 16 between its end I! and B5 is apertured at I06 (Figure 3) to freely receive a threaded stud IIlI carried by plate 22. An elongated, knurled, stop nut I08 having a conical abutment end I99 is threaded on stud I9! and provides an adjustable stop designed to limit the pivotal movement of lever 16 in a clockwise direction around pivot 11 and to predetermine the length of stroke of nut feed bar 61 to prevent feed bar 61 from being pressed between platen H and die mechanism A if it should happen that no nut was in passage II to be positioned in pocket I5.

Nuts are fed to feed barsfi! from a tray I I I carried by the upper ends of chutes H2 mounted on rails 63 by means of cap screws I I2. Each chute H2 is provided with aligned spherical nut stop members I I3 (Figures 14 and 17) which protrude through suitably formed openings in the side walls of chute H2. Stop members H3 are normally held against the peened overportions of the openings by means of coil springs H4, the tension of which may be adjusted by knurled screws H5 adapted to be locked in position by lock nuts II 6. As clearly seen in Figure 17, a portion of the spherical stops H3 protrudes into chute I I2 to engage the side walls of nut I I passing down chute H2 to position the nut for engagement by a nut feed pick-up finger tovbe presently described. It will be clear that adjustment of the tension of springs H4 varies the resistance to downward movement of nuts II so that the stop means may be varied to just over come the weight of nuts above stops I I3 to assure the smoothest possible operation of the feed mechanism. The side walls of chute H2 upwardly from stops H3 are bridged by a strap member I I1. supporting a spring finger I I8 which extends along the space H9 between the side walls of chute H2 and has its end H8 over-' lying stops H3.

Centrally disposed longitudinally extending slots I22 aligned with the axis of the opening in nut II are formed in the bottom walls of chutes H2. These slots are designed to freely receive a narrow pick-up finger I23 carried on the free end of a pivoted arm I24 which is pivotally mounted in slot 68 of feed bar 61 on a pin I25. A coil spring I26 seated "in a recess I21 in bar 61 normally biases arm I24 to its upper position with the end finger I23 i horizontal alignment with the opening in nut II when the nut is engaged with stops H3 as clearly seen in Figure 14. A suitable stop screw I28 threaded into feed bar 61 limits counter-clockwise rotation of arm I24 around pivot I25 and provides adjustable means for varying the normal position of finger I23. Rollers I29 are provided on the upper end of arm I24 and are designed to engage with the under surface of chute H2 as feed bar 61 moves to the right so as to cam arm I 24 downwardly in a clockwise direction and prevent finger I23 from pushing the nut out of chute II 2. At its lower end, passages H9 of chutes H2 discharge into spaces 'H between rails 63 and are provided with a weight operated flap valve or member I39 pivoted at I3I so as to normally lie in passage II adjacent the lower end of chute I I2 and prevent nuts II released from finger I23 from gravitationally sliding into the path of the indenting die A.

In operation, nuts in tray III are fed by hand into the upper end of chute H2, which as seen in Figure 17 is of a width sufiicient to just receive the flats of the nuts, and slide down into engagement with stops H3 with one of the corners disposed downwardly of the chute. Assuming that motor M is operating and shaft 34 is ro tating in a counter-clockwise direction, crank shaft 9| will be rotated in a counter-clockwise direction causing crank disk 89 to rotate in a counter-clockwise direction and move connecting rod 81 to the left as viewed in Figures 3 and 15. This movement of connecting rod 81 rotates lever I6 in a clockwise direction around pivot IT until it engages abutment portion I09 of stop nut I98 and moves feed bar 61 to the right as seen in Figures 3 and 14. As feed bar 61 'moves to the right, finger I23 is moved into engagement. with surrounding rods I38.

the opening in'nut H positioned by stop mem-: bers I I3 and pulls the nut past the stop members and beyond theend 'I I8 of finger II8. During this operation the end I33 of feed bar 61 (Figures 4 and 14) engages the nut located in passage II and moves it to the right into nut receiving pocket I positioning the nut under die mechanism A and holding it in position under the force of spring 93 during the indenting process. During this movementof nut II along passage II, flap valve I38 is cammed upwardly allowing the nut to pass beyond it into pocket 15 and then drops back upon feed bar 61 which upon retraction permits the flap valve to fall back into place in passage II. During the retraction of feed bar 61 finger I23 moves the nut II engaged by it backward up chute II2 into engagement with end II8 of finger H8 and upon continued retractile movement frees the nut and permits it to slide down chute II2 into position in passage II. It will thus be seen that nuts are automatically fed one at a time to the receiving and positioning pocket I5 and that inadvertent jamming of nuts in passage II is automatically prevented.

Referring particularly to Figures 3, 6, 12 and 14, the drawings illustrate a preferred form of yielding pressure means for limiting the relative movement of platen H and die assemblies A.

While any suitable yielding pressuremeans, such as apre-loaded spring means or' fluid means, may be used, the pre'sent invention preferably utilizes fluid backed pistons P carried by piston rods I38 and mounted in cylinders I39. While cylinders I39 may assume any desired form, they are illustrated as open ended cylindrical mem bers, the upper ends of which are seated in recesses I4I formed in cylinder heads I42 bolted to bridge portion 21 of superstructure C (Figure 6). The opposite ends of cylinders I39 are seated in recess I43 formed in cylinder heads I44 mounted on the lower ends of studs I45 carried by heads I42 bymeans of nuts I46. Spacing sleeves I4'I surrounding piston rods I38 limit the downward movement of pistons P toward cylinder head I44. Cylinder heads I44, as clearly seen in Figure 6, are provided with stufling boxes I48 Suitable packing I49 in stufiing boxes I48 prevents the passage of liquid along rod I38 and serves as a seaL. To prevent liquid from leaking aroundthe. ends of cylinders I39, any suitable'sealing means such as gaskets (not shown) may be interposed between the ends of cylinders I39 and thefbottom of recesses MI and I43. Furthermore, spacing sleeves I41 are preferably welded to cylinder head I44as shownat I5I. to prevent themirom rising upon upward movement of pistons P; l e lower ends of piston rods I38 are externallythreaded' at I52 (Figure l2) to receive adaptor members I54 designed to receive indenting, dies I55 shown in detail in Figures 8 and 9. Lock nuts I56 threaded on portions I52 of piston rods I38 lock adaptors I54 in adjusted position. As clearly seen in Figure 14, adaptors I54 may be adjusted along threaded sections I52 in order'to make fineadjustments of the heightof, indenting dies I55. To assure proper angularpositioning of dies I55, each piston rod I38 is provided with a collar I51 having a set screw .I58 design ed to lock} collar) I5'Iato rod I38. ,Each collar is provided with diametrically opposed flats I59 adapted to receive one end .of a strap member I59. As seenin Figures 1 and 12, theadjacent ends of strap members I68 are connected to one collar by pivot screws m l and 10 the opposite adjacent ends are similarly connected to the other collar I51. As a consequence, each strap member is freely pivoted at itsends to collars I51 50 that independent vertical movement of rods I38 is not impeded. However, angular movement of each rod I38 is opposed by the other when set screws I58 are tightened through straps I69 and collars I5'I. To adjust the angular position of either rod and its associated die A, it is merely necessary to loosen the associated set screw I58 and turn the rod in its collar I5'I. This construction, accordingly, serves to permit independent angular adjustment of rods I38 and the associated die A without affecting the height above platen H and also as a lock or key toprevent rotation of rods I38 during operation of the machine. It will thus be seen that very accurate positioning of the dies with respect to the platen H and the nuts in pockets I5 may be accomplished by this adjustment and that manufacturing inaccuracies which might occur and cause deviations between the height of the respective dies above the platen H may be readily compensated.

Referring to Figures 1 to 3 and 6, the manner of supplying liquid to piston P will now be described. As clearly seen in Figure 6, cylinder heads I42 are provided with L-shaped passages I6I, one end of which leads into the portion of the cylinder above piston P and the other end of which is connected by means of pipes I62 to outlet connections I63 of tank T. Suitable valves I64 are preferably provided to cut off the flow of liquidfrom ta'nk T to cylinders I39 when desired. Suitable drain pipes I65 provided with closure caps I66 are also connected to member I63 to drain tank T when desired. Cylinder heads I44 are likewise provided with L-shaped passages I6I connected by means of pipes I68 to position under substantially the same pressure imposed. upon the fluid in tank T. Assuming that nuts have been positioned in pockets l5 and that platen H is moved upwardly by cams 31, the nuts will be brought into engagement with dies I and relative movement-between platen H and dies I55 will continue until the downward force of the associated piston is overcome by the upward force against the particular die I55. When this downward force on either piston is exceeded by the upward force on its associated die I55, piston P will rise off of spacing sleeve I41, such movement being permitted by flow of fluid through pipe I62 into tank T and compression of the air in the upper portion of tank T. Continued upward movement of platen H will cause the platen and die and nut to move as a unit. Since the surface area of the fluid in tank T is substantially greater than the surface area of pipe I62 and piston P, it will be appreciated that a very slight compression of the air in tank T occurs by reason of movement of one or both pistons P. As a. consequence, no appreciable differencein the yielding force results and the degree of indentation of each nut will be substantiallyidenticjal; Accordingly,. since the troublesome'variations in tnutheight and density encountered in standard quantity production nuts groan? 11 l is relatively small, the movement of pistons P is very slight and any variations in the pressure in tank T caused by the flow of fluid through pipes I62 can be wholly disregarded.

Furthermore, by definitely predetermining the area of the indenting prongs I13 and the height of the effective indenting portions of said prongs, thereacting pressure on piston P through piston rods I38 and the degree of indentation may be accurately predetermined since the upward reacting pressure is determined by the area of contact between the prongs and the metal of the nut multiplied by the force acting against the dies. Since this force is, as a practical matter, constant' for each stroke of the cam, the area of engagement between the prongs and nut is the variable factor determining the degree of indentation and is directly related to the yielding pressure.

As a specific example, it has been determined that the indenting prongs of the present invention will be satisfactory if the prongs are made triangular at their ends and the triangular ends are ground fifteen degrees sidewise and fifteen degrees back-off. While not necessary, the inner edges of the prongs are preferably sufliciently sharp to slightly out the metal of the nut above the root of the thread. Furthermore, the radial distance from the center of the die to the lowermost points of the indenting prongs, which are adjacent the center of the die, should be such that the distance of the innermost line of the indentation in the nut is about of an inch outwardly from the root of the thread in a /2- inch nut. Prongs I13 of the desired form and spacing are preferably carried by a. removable auxiliary body section I M designed .to be threaded into main body section I'i5 threaded at I'Ifi for engagement with adaptors I54. Such sectional dies permit ready interchangeabilit and are very desirable. Following these general specifications for constructing the dies, extremely satisfactoi y lock nuts having definitely controllable gripping characteristics havebeen made by the deflecting machine of this invention and such nuts are meeting with unprecedented approval in the trade. It is to be understood, however, that variations in the shape of the dies and the dimensions given above may be made without avoiding this While any means may be provided for replenishing the fluid in tank T, the present invention provides a pump Q bolted to one end wall 23 by cap screws ISI (Figure 1) Pump Q has-an inlet port I82 (Figure '7) provided with a one way valve I33 and is connected to the reservoir R by means of a pipe line I84. Pump Q is preferably of the piston type having a piston I85 provided with a downwardly extending actuator rod I86 and a spring I81 normally holding piston I85 in its downward position. An outlet port I83 having a one way valve I 89 thereinis connected through a pipe line I9I to tank '1. Thelower end of actuator rod I St is adapted to be contacted by an actuator member 592, pivoted to platen H, when member I92 is in the position shown in Figure l, to move the piston upwardly against the resistance of spring 18? to force liquid into tank T. I The spring returns the piston in well known manner. Member I32 has a handle I93 to. be grasped by the operator to selectively render pump Q inoperative, if suflicient liquid is in tank merely-by turning member I92 to its inoperative position as shown in Figure 12. A bleed line I94 is connected to pump Q below the piston to drain any liquid, that might by-pass the piston, back into reservoir R. It will thus be seen that a selectively operable pumping system is provided by the present invention to maintain a suificient quantity of liquid in tank T. v p

To care for a situation wherein too much liquid may be in tank T, thpresent invention provides a pipe line I 9! containing a cut-01f valve I98 lead; ing from tank T to reservoir B. By manipulating valve I98, excess liquid in tank Tcan be readily drained off into reservoir R. During normal operation of the machine, it will be appreciated that valve I98 is closed to enable the desired pressure to be maintained in tank T. Since valve I89 in pipe line I9 I is normally closed and is forced into closed position by pressure in pipe line I91, it will b appreciated that no loss of pressure can occur through this line. V

To measure the pressure-in tank T, a pipe line 290 leading from tank T is provided with an upwardly extending extension 28! carrying the pressure gauge G. 7

To automatically eject completed nuts from pockets 15, the present invention provides air nozzles 283 disposed with outlet ends adjacent each pocket I5. Nozzles 283 are connected by pipe lines 204 to a T-shaped union 205. Union 205 is carried by a pipe line 205 secured to the back edge of platen H by a strap 2B6. Pipe line 235 is connected by a flexible hOSe 201 to the valve V which P is in turn connected through a pipe line 258 to a T-coupling in pipe line I69. While valve V may assume any suitable form, it preferably comprises a poppet valve 209 cooperating with a valve seat 2I0 which opens into a chamber 2II in a valve body 2!2 (Figure 4). As clearly seen in this figure, poppet valve 2539 has an elongated stem 2 I3 which extends through a wall of body 2H! and through a coil spring assembly 2 I4 disposed between said wall and a contact head 2 I 5 removably secured to the end of stem 2 I3. Spring assembly 2M is normally loaded to bias pocket valve 253 into sealing engagement with seat 219 to out off the supply of air from pipe line I69 except when desired at the proper time in the sequence of operation of the machine.

Air is supplied to nozzles 28,3 at the proper moment by one of thecams 31,, one side of which, out of the path of roller 53, is providedwith cam-like member ZIB arranged to contact a pivoted valve actuator 2 I! journalled at 2 58 on an arm 2 I 9 formed integrally with or secured to the valve body 2 I2. Referring to Figured, it will be noted that member 2 I6 is adjacent tothe highest point of can-1,31 so that valveZflB is opened momentarily when platen H is-at-its lowermost point when the nut is out of contact with the indenting die. This momentary opening of valve 209 directs a blast of air against a flat side of eachof the nuts in pockets I5 through nozzles 233 and 'pro-. jects thenuts toward the center of the machine into a discharge chute 22I having a rearwardly tapering, centrally disposed,,def lecting member 222 (Figures 12 and 13) and a cover plate 223 bolted thereto by means of screws 224.

Actual experience has shown that a blast of air from nozzle 203 is suflicient to remove the nuts from pocket 15 and project them along the rearwardly directed walls of member 222 and into a suitable receptacle on the floor at the rear of the machine.

While the present machine includes a pair of nut receiving pockets I and die mechanisms A along with their individual feed bars 61, guide rails 63, chutes H2 and pressure lines, it will be understood that any number of dies, nut pockets, feed bars and the like may be employed by suitable modifications apparent to those skilled in the' art. This invention, accordingly, is not to be limited to the specific machine disclosed but it is intended to be coextensive with the appended claims to which reference should be made to determine its scope.

v The invention may be embodied in other specific-forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the inventionbeing indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

'1. A machine for making lock nuts of uniform gripping or locking force from nuts of varying heightand density formed by standard quantity production methods, comprising a pair of members mounted for relative movement toward each other" and operable to press a nuttherebetween, one of said members being adapted to support said nuts and the othercomprising shallow means of rapidly varying area operable to indent a face of a supported nut and modify the helix angle of a portion of the threads of said nut in proportion to the depth and area of indentation; driving means for imparting a reciprocating movement to one of said members, to bring the mem- 'bers into pressing relationship with the nut; and additional means for applying pressure'of predetermined value to one of said members in opposition to said driving means to limit further relative movement of said members and assure indentations of substantially identicaldepth and area with-a substantially identical-modification inthread helix angle and a-uniformmgripping force in nuts of varying heightand density.

2. "The combination defined in claim '1, wherein'said shallow means'of rapidly varying area I simultaneously deflects the metal of thenut axipredetermined magnitude, to permit unitary movement of said members and said nut; and shallow indenting means of rapidly increasing surface area carried by one of said members and adapted to-axially and laterally indent afaceof said nu-t during such further relative movement of said members, and'eifect deformation of only the helix angle of the nut thread, said indent ing meansbeing so designed that the pressure developed between said members and said nut increases at a greater rate than the degree of axial indentation until said predetermined pressure is attained-whereby said machine is operable to impart identical locking forces to nuts of varying'height and density. 4. The machine defined in claim 3, wherein said driving means comprises a rotating shaft having a cam operable to constantly engage said one member, and said one member is provided with means for resiliently maintaining engagement between it and said cam.

V 5. A machine for forming a lock nut having. a modified helix angle comprising a base; a supporting member on said base for supporting a nut'receiving plate; a drive shaft journalled on said member; means for guiding said nut receiving platefor'vertical reciprocation on said supporting'member in apredetermined path; cam means on'said drive shaft for reciprocating said nut receiving plate; a hydraulic cylinder supported above said plate; a pistonoperatively associated-vvith said cylinder; a closed fluid tank,

ally of and laterally in all directions away from the nut opening during said pressingoperation, the axial and'lateral deflections being in definite containing a body of liquid exposed to a volume of air, the area of the surface of the liquid being substantially larger than the area of said piston, means connecting said tank tosaid cylinder, to supply fluid to said cylinder and providing an air cushion for yieldingly opposing flow of liquidfrom said cylinder; an indenting die c'a'rried by said piston and maintained in predetenminedspaced relation to said nut receiving plate by th'e'fiuid in-said cylinder; and means for driving said drive shaft to reciprocate said nut receiving plate toward said die to press a nut supported thereon against said die, whereby a face of said nut is axially indented to only deform the helix angle of the nut thread adjacent the indented area to the extent permitted by the pressureofsaid fluid.

6.-In a machine having relatively movable membersoperable 'to successively press nuts therebetween at an indenting station to indent a face-of said nuts and modify the helix angle to secure a locking action, a drive shaft having a predetermined ratio and the area of saidmeans 1 cam for producing said relative movement of said being designed to assert a rapidly increasing resistance to penetration of said means upto the point wheret'he resistance balances the pressing force, and-to automatically and accurately limit the modification of the helix-angle.

"3; A'mchine for making-lock nuts of uniform gripping or looking force from-huts formed by standard quantity: production methods, comprising a pair of members mounted for relative moveopposition to said driving means to permit furtherrelative'mcvement of said members until a pressurepf predetermined magnitude is built up between said membersan'd theig rippedrnut, and

operable, upon'attainm'ent of said pressure of members, a nut receiving pocket at said indenting station for positioning said nuts; gripping means for holding nuts in said receiving pocket while said nuts are pressed between said members; means for actuating'said gripping means, comprising a lever pivoted between its ends and having one end pivotally connected to said gripping means ,toimpart the desired movement thereto; a driven shaft operatively driven by said drive shaft and having a crank positioned thereon in predetermined relation to said cam on said drive shaft to assure proper timed operation of said gripping means; a rod interconnecting said crank and said lever and having relatively endwise movablesections, for actuating said gripping meansin response to rotation of said crank; and resilient means acting between said rod sections and operable to automatically'comgpensatejfor variations in the length of stroke of 5 said gripping means to compensate for-variations 15 in size of said nuts and to retain said nuts in said receiving pockets under a yielding engagement pressure while said members press the nut therebetween.

7. The combination defined in claim 6, together with stop means for limiting the range of oscillation of said lever and the stroke of said gripping means, to prevent injury of theparts in the event no nut is in said receiving pocket during actuation of said gripping means.

8. In combination with a nut indenting machine having a reciprocating nut gripping slide, a downwardly sloping nut supply chute, having a bottom wall provided with a longitudinally extending slot, and side walls, for delivering nuts to the gripping end of said slide; spring pressed members mounted in said side walls and protruding into said chute in position .to yieldingly arrest downward gravitational movement of nuts along said chute; a pick-up means carried by said slide and operable, upon reciprocation of said slide in one direction, to pass through said slot and engage a nut held by said members and draw it downwardly in said chute past said members; and means operably associated with said chute to prevent the engaged nut from moving upwardly in said chute during the return stroke of said slide and cause said nut to be freed from said pick-up means and delivered by gravity into position to be gripped by the gripping end of said slide during its next reciprocation.

9. Nut feed means for use with a nut indenting machine having a nut receiving pocket; a die for indenting a nut disposed in said pocket; and pressure means for imparting relative movement to said pocket and die to indent said nut; comprising means aligned with said pocket for guiding a nut into said pocket; means for moving a nut along said guide means into said pocket; means for driving said nut moving means in timed relation to said pressure means; a chute for delivering nuts to said nut guiding means; resilient means in said chute to yieldingly arrest gravitational movement of a nut along said chute; nut releasing means carried by said nut moving means for engaging a nut held by said resilient means upon movement of said nut moving means toward said pocket, and operable to propel said nut along said chute past said resilient means;

and a second resilient means bridging said chute.

in the region of said first resilient means for engaging said nut upon reverse movement of said nut moving means to free said nut from said nut releasing means, whereby said nut is freed to slide down said chute into said nut guiding means in position to be moved into said pocket.

10. The combination defined in claim 9, together with pivoted means associated with said nut guiding means to arrest movement of a nut delivered from said chute until the delivered nut is picked up by said nut moving means.

11. The combination defined in claim 9, wherein said nut guiding means and said chute are of a width to position the nut with a corner facing forwardly with respect to said nut feeding means, and said'pocket is shaped to receive said corner and is adjustable transversely of the die axis, to assure proper alignment of said nut with the path of movement of said die.

12. The combination defined in claim 9, wherein said nut releasing means is pivoted to said nut moving means and is provided with rollers adapted to engage the underside of said chute and compel said nut engaging means to move 16 longitudinally of said chute to draw said nut past said resilient means.

13. Nut feeding means for anut indenting machine, comprising a nut receiving chute and a reciprocablebar, an arm pivoted at one end on said bar and having a nut engaging finger at its free end for entering the opening in a nut; resilient means acting upon said arm and constantly tending to swing the free end of said arm away from said bar; stop means on said bar engaging said arm and limiting swinging movement of the arm away from said bar whil permitting free movement of the arm toward the bar against the action of said resilient means and means mounting said stop means for adjustment, for predetermining the spacing between said bar and said free end of said arm.

14. A machine for imparting a uniform gripping or looking force to nuts which have been produced by standard quantity production methods, comprising a movable nut indenting die; fluid pressure means resisting movement of said die with a predetermined opposing force; reciprocating means for moving a nut into pressing contact with said die; a reservoir containing fluid for supplying fluid to said fluid pressure means; a reciprocating pump connected to said fluid pressure means and said reservoir for delivering fiuid from said reservoir to said fiuid pressure means; and means on said nut moving means adapted to be selectively positioned to operate said pump and replenish said fluid pressure means in response to reciprocations of said nut moving means, as required.

15. In a nut indenting machine for converting standard quantity production nuts into lock nuts of predetermined locking force by pressing nuts between a pair of opposed movable members including indenting dies, means for predetermining and controlling the pressing force to which said nuts are subjected, comprising expansible chamber means operably associated with one of said members; a body of liquid acting on said expansib-le chamber means and connected through a confined column of said liquid to a larger body of said liquid contained in a closed tank, said tank providing a confined body of air above said larger body of liquid; means for delivering compressed air to said tank and maintaining the pressure on said larger body of liquid substantially constant, said expansibl chamber means being so disposed that the pressure therein is directly proportioned to the pressure built up between said members and said nut, and embodying relatively longitudinally movable parts; and means for restraining the latter against movement under the influence of said liquid pressure, while permitting free movement thereof in the opposite direction when the pressure between said members and said nut has built upytoa predetermined magnitude.

l6. The-combination defined in claim 15, wherein said first-mentioned member includes a plurality of spaced independently movable indenting dies and said expansible chamber means comprises independent pistons connected to said dies by separate, spaced, parallel piston rods, together with means interconnecting said piston rods to prevent rotation of said piston rods, pistons and dies, while permitting limited independent axial movement thereof.

17. In a ,nut indenting machine having a. base and superstructure for supporting a nut indenting die and a movable platen for supporting a nut and moving it into indenting relation, guide means comprising parallel v-ways in said superstructure parallel to the axis of said indenting dies; and V-guide members carried by said platen and snugly but slidably fitting in said ways to accurately guide said platen in a path parallel to the axis of said die and prevent tilting of said platen.

18. In a. machine for converting standard commercial nuts into lock nuts by indenting an end face of the nut to distort the threaded bore thereof, a. nut indenting member and a nut supporting member relatively movabletoward and from each other, power operated means for reciprocating said nut supporting member to establish an engaged relationship between said indenting member and the nut, said indenting member having a nut penetrating part, and pressure means opposing unitary movement of said members by' the power operated means and having a Value determined by the desired depth of penetration of the nut by said part, said pressure means being connected with and controlling the entire effective operation of the indenting member independently of said power operated means, whereby uniform penetration of the indenting part and distortion of the nut thread is obtained irrespective of variations in axial thickness and structural density of difierent nuts.

.19. In a machine for converting standard commercial nuts into lock nuts by indenting one end face of the nut to distort the threaded bore thereof; a nut indenting member and a nut sup- 7 porting member, power operated means to move and density by said indenting member.

20. The combination defined by claim 19 in 18 which the eiiective action of said pressure means is controlled exclusively by the resistance of the nut to penetration by the indenting member in the relative movement ofsaid members.

21. The combination defined by claim 19 in which said power operated means is operatively connected with the nut supporting member.

22. In a machine for providing standard commercial nuts with self-locking characteristics, a nut indenting member, a nut receiving station having means to position a nut for engagement by said member, a supply chute through which nuts are directed by gravity towards the receiving station, a reciprocable slide for advancing a nut discharged from said chute to the nut receiving station, means for releasably arresting gravity movement of nuts in said chute, and means feeding and gripping slide in timed relation to each other.

24. The combination defined by claim 22, in which said slide operated member, in the advancing movement of the slide, engages and moves the nut in one direction in the chute against the resistance of said arresting means, together with a relatively fixed stop engaging the nut in its movement in the opposite direction with said member as the slide is retracted, to release said nut for gravity discharge from the chute.

CHESTER, D. TRIPP. 

